462 THE NETPIERLANDS. 



level as the actual beach. lie is of opinion that the settling down of peat 

 bogs and mud-banks satisfactorily accounts for the instances of subsidence 

 observed. The polders along the coast regularly settle down after they have 

 been dyked off, the Bylmenneer being a notable instance : its bed has sunk 1*() 

 feet in the course of twenty-five years, the effects of drainage and the pressure 

 of roads and houses satisfactorily accounting for this phenomenon. The beds 

 of the ancient polders along the Dollart are about 7 feet lower than those of 

 polders only recently created. Tliere are, of course, limits to this subsidence, 

 which varies moreover according to the nature of the soil. The bed of the polder 

 of Enkhuizen sank 52-16 inches between 1452 and 1616, or at the rate of 032 

 inch annually. Between 1616 and 1732 the subsidence only reached one-third 

 of that amount, and no change whatever has taken place since. 



Holland has sometimes been likened to a leaky ship slowly sinking to the 

 bottom ; but it appears quite clear that, though the country subsides, this subsidence 

 is confined to the upper strata of the earth's crust, and that there are consequently 

 limits to its extent. Still the fact of considerable tracts of land having disap- 

 peared beneath the waves remains. A fringe of islands approximately marks 

 the ancient extent of the coast-line, now deeply penetrated by the estuaries of 



Fig. 257. — Sectiom of the Dyke of Westkafpel. 



KiiiLWAVTHAe/r •% 



the Schelde and Rhine in the south and by the Zuider Zee in the north. The 

 maritime face of the country is thus cut up into three distinct portions, viz. the 

 archipelago of Zealand in the south, the peninstda of Holland in the centre, and 

 the island-fringed Friesland in the north. 



The area occupied by dunes is larger than in Belgium, and these sand-hills 

 attain a greater height. The Blinkert-duin, near Haarlem, rises 197 feet, and stand- 

 ing upon its summit, that part of Holland which has been the scene of the most 

 important historical events lies spread out beneath us as far as Amsterdam. 

 The humid atmosphere consolidates the dunes, and in some instances they are 

 covered with a spontaneous growth of mosses, which would prevent their advance, 

 if it were not for the burrows of rabbits. Elsewhere they have been planted, 

 and, upon the whole, they form the best barrier against the ocean that could 

 be devised. They but rarely invade the land, and if the sea encroaches never- 

 theless, this is due, not to an advance of the dunes, but to the erosive action of 

 currents and breakers, which undermines them. 



A great deal of the national energy has been devoted to the reclamation of the 

 submerged lands. It has been computed that 2,336 square miles of land have been 

 swallowed by the sea since the thirteenth ceutury, of which 1,476 square miles 



